Charles S. Elton and the dissociation of invasion ecology from the rest of ecology Blackwell Science, Ltd MARK A. DAVIS1,*, KEN THOMPSON2 and J. PHILIP GRIMES, Department of Biology, Macalester College, Saint Paul, MN 55105 USA, 651–696–6102, *Corresponding author, E-mail: email@example.com; 2Department of Animal and Plant Sciences, The Universityof Sheffield S10 2TN, UK
Abstract. Despite several decades of research, the field of invasion ecology has not been very successful in developing reliable generalizations regarding the mechanisms and predictability of invasions. In this essay, we argue that one impedi- ment in the field’s development has been that the field of invasion ecology has largely dissociated itself from other subdisciplines of ecology, par- ticularly succession ecology. Taking an historical approach, we suggest that this dissociation began with Charles S. Elton, the generally acknowledged father of invasion biology. We argue further that, despite periodic calls to end what some have regarded as a spurious distinction between native colonizers and introduced invaders,
INTRODUCTION Species invasions are widely recognized as a serious threat to environments and economies throughout the world (Wilcove et al., 1998; Dukes & Mooney, 1999; Pimental et al., 2000). Unfortun- ately, ecologists have not been able to provide much assistance to land managers because the field of invasion ecology has progressed so slowly. A recent assessment of the field has concluded that it is still largely anecdotal, with few reliable generalizations (Williamson, 1999). We believe that the field’s development has been hampered for decades due to an unfortunate dissociation from other fields of ecology, particularly succession ecology. The dissociation of invasion ecology from succession ecology is apparent from any casual invasion ecology has continued to pursue its own generalizations with limited success. We suggest this dissociation may be exacerbated further by incentives produced by the realities of publishing and securing funding for research and also by the use of electronic search engines to identify related articles. We offer several examples of how invasion ecology has benefited from research on succession and regeneration conducted on native species and conclude that the field of invasion ecology would do well to do more of this type of communica- tion and collaboration among subdisciplines. Key words. Biological invasions, invasion ecology, succession, Charles Elton. examination of the bibliographies of papers from the two fields. Each seldom cites the other. For example, three of the most recent and thorough assessments of invasion ecology are by Lonsdale (1999), Williamson (1999), and Dukes & Mooney (1999). Together the three articles contained 182 citations. Of these citations, 106 included the words ‘alien’, ‘nonindigenous’ and /or some form of the word ‘invasive or invader’. Not one cita- tion includes the words ‘succession’, ‘recovery’, or ‘secondary’. A very different pattern is revealed by a review of the bibliographies of recent succes- sion articles. For example, three recent articles on subalpine forest succession ( Donnegan & Rebertus, 1999), tropical succession (Hughes et al., 1999) and succession following hurricanes, volcanic eruptions and massive forest fires (Turner et al., 1997) contain 202 references combined.